docs: def _check_tbit(self, **keys):
          """
          Check if one of the columns is a TBIT column
  
          parameters
          ----------
          colnums: integer array, optional
          """
          colnums = keys.get('colnums', None)
  
          if colnums is None:
              colnums = self._extract_colnums()
  
          has_tbit = False
          for i, colnum in enumerate(colnums):
              npy_type, isvar, istbit = self._get_tbl_numpy_dtype(colnum)
              if (istbit):
                  has_tbit = True
                  break
  
          return has_tbit